VitaRelay

Reconstitution calculator

Enter the amount of drug substance in the vial, the volume of diluent you added, and the mass you intend to measure. The calculator returns the resulting concentration, the draw volume in milliliters, the equivalent mark on an insulin syringe, and how many doses of that size the vial contains. Load a common vial configuration to save typing, or work through it step by step. For full technique, read the reconstitution guide.
Inputs

0.3 → 0.9 → 1.8 → 3.6 mg weekly SC, +1 step every 4 wks (Phase 2/3 ladder). These are common vial and diluent configurations for arithmetic only — every field stays editable, and the prescription governs the amount actually measured.

U-100 barrels are marked 100 units per milliliter.

Concentration
1.5 mg/mL
1500 mcg/mL
Volume per dose
0.2 mL
on a U-100 barrel
Syringe units
20 units
100 units = 1 mL
Doses per vial
10
10 including the remainder
How this was calculated
  1. Concentration = drug substance ÷ diluent volume.
  2. Volume per dose = dose ÷ concentration.
  3. Syringe units = volume per dose × 100.
  4. Doses per vial = drug substance ÷ dose.

The calculation assumes the powder contributes negligible volume, which is the usual working assumption for small-mass lyophilized cakes. Where the final volume is stated on the pharmacy label, use the label.

What this tool does and does not do

It converts between mass, volume, and syringe graduations. The presets load a vial size, a diluent volume, and a reference amount that are commonly used for that compound so the arithmetic can be checked quickly — they are configuration shortcuts, not clinical advice, and they do not apply a protocol or account for any individual patient. Nothing is locked: overwrite any field, or choose manual entry to start from an empty form.

The correct amount for a given patient is a clinical decision made by the prescriber and recorded on the prescription. Where the dispensing pharmacy's labeling states a final volume or concentration, the label takes precedence over anything computed here.

Everything is computed in your browser. Nothing entered here is transmitted, stored, or logged.

Keep reading

Reconstitution guide
Diluent selection, aseptic technique, dissolution, and labeling.
Reading insulin syringes
What the units returned above mean on a U-100, U-50, or U-40 barrel.